This invention relates to an improvement to a tape cassette with a lid for recording and playback which makes it easy to carry out assembly of the tape cassette and particularly relates to a structure with which when fitting an upper shell with a lid mechanism assembled thereto in an open state onto a lower shell it is possible to fit the upper shell onto the lower shell from above the lower shell with one straight movement.
A lid part h of the kind shown in FIG. 2 is mounted on this kind of cassette having light beam transmission apertures b for detecting the ends of the tape. This lid part h has a pair of side portions i at its ends. These side portions i each have a shaft portion, and the lid part h is mounted on the cassette proper a pivotally about these shaft portions j between an open position wherein it exposes the tape c and a closed position wherein it covers the tape c.
Although not shown in the drawings, these side portions i are provided with openings which when the lid part h is in its open position are aligned with the light beam transmission apertures b in the cassette proper a and allow light beam f to pass from the light source e to the sensors g.
When the lid part h is in its closed position these openings are not aligned with the light transmission apertures b and dust from outside is prevented from entering through the transmission apertures b.
Even when this lid part h is in its closed position with respect to the cassette proper a, there is a gap k between the area of the cassette proper a around each light beam transmission aperture b and the lid part h. Because of this there has been the problem that even when the lid part h is in its closed state dust enters the cassette proper a through the gap k and the transmission apertures b and adheres to and adversely affects the tape c.